A study of highly sensitive D-shaped optical fiber surface plasmon resonance based refractive index sensor using grating structures of Ag-TiO2 and Ag-SnO2

• Published in: Optik (Stuttgart) 2022-02, Vol.252, p.168527, Article 168527
• Main Authors: Dubey, Sarvesh K., Kumar, Anil, Kumar, Awadhesh, Pathak, Amit, Srivastava, S.K.
• Format: Article
• Language: English
• Subjects: Finite element method (FEM); Grating; Near-Infrared (NIR); Refractive index (RI); Surface plasmon resonance (SPR); Surface plasmons (SPs)
• ISSN: 0030-4026; 1618-1336
• DOI: 10.1016/j.ijleo.2021.168527

In this study, we propose a design and simulation of a highly sensitive surface plasmon resonance (SPR) based single-mode D-shaped optical fiber refractive index sensor in the near-infrared (NIR) region. It consists grating structure of silver coated with titanium dioxide (TiO2) and Tin dioxide (SnO2) layer on the core-cladding interface. With the help of the finite element method (FEM), the proposed optical fiber sensors are optimized with various geometrical parameters. Proposed optimized structures are investigated and various performance parameters are calculated. It is found that performance parameters enhance with TiO2/SnO2 coated on Ag grating structure at a particular thickness of TiO2/SnO2. Due to this more generations of surface plasmons take place on metal-metal oxide structures. We find the maximum sensitivity of 15.31 μm / RIU and 9.81 μm / RIU for Ag-TiO2 and Ag-SnO2 grating structure respectively which shows a better result in comparison to the other reported work. So proposed structure may have great potential to enhance the sensing ability of optical fiber-based sensors as compared to the other conventional SPR based optical fiber sensors. •In the present work, we optimize D-shaped optical fiber SPR based refractive index sensors with grating structure of silver (Ag) coated with TiO2, SnO2 layers separately by using Finite Element Method (FEM).•It is observed that the good SPR generation occurs for thickness of Ag (65 nm)-TiO2 (10 nm) grating and Ag (45 nm)-SnO2 (17 nm) gratings in a separate optimized configuration.•Our simulation demonstrates that, the maximum sensitivity 15.31 µm/RIU and 9.81 µm/RIU in Ag-TiO2 and Ag-SnO2 configuration respectively for 1.33–1.355 RI range.